In the air quality directive (2008/EC/50), the EU has set a limit value for benzene (C6H6) for the protection of human health: the annual mean value may not exceed 5 micrograms per cubic metre (µg/m3). The limit value comes into effect for data measured from 1 January 2010. During 2009 a margin of tolerance was in place so the annual mean should not exceed 6 micrograms per cubic metre (µg/m3).

In the air quality directive (2008/EC/50) the EU has set two limit values for nitrogen dioxide (NO2) for the protection of human health: the NO2 hourly mean value may not exceed 200 micrograms per cubic metre (µg/m3) more than 18 times in a year and the NO2 annual mean value may not exceed 40 micrograms per cubic metre (µg/m3). These limit values come into force for concentrations measured from 1.1.2010 so during 2009 a margin of tolerance equal to an annual mean value of 42 micrograms per cubic metre (μg/m3) is still in place.